Getting the wall coordinates from IFC file with XBIM

Question

I need to get the list of vertices of IfcWall object using XBIM. The code i need must look something like:

using (model)
{
    List<ItemSet<IfcCartesianPoints>> loppsList = new List<ItemSet<IfcCartesianPoints>>();
    var walls = model.Instances.OfType<IfcWall>();

    foreach (var wall in walls)
    {
        loppsList.Add(wall. ... .Points);
    }
}

But i have no idea, how to get the proper way .

I tried the solution proposed here: IFC objects navigation to retrieve Wall coordinates

foreach (var wall in walls)
{
    var line = wall.Representation.Representations[0].Items[0];
    var _line  = line as IfcPolyline;
    loppsList.Add(_line.Points);
}

But i didn't get the proper data — maybe I just got lost in the path of attributes. Please help to navigate through the IfcWall attributes.

score 1 · Accepted Answer · answered Jan 12 '20 at 16:46

Ok, if someone in future will face the same question, the full way is:

wall.Representation.Representations[].Items[].Outer[].CfsFaces[].Bounds[].Bound.Polygon[]

//this is how i print the x coordinates of all points
using (model)
        {

            var walls = model.Instances.OfType<IIfcWall>();

            foreach (var wall in walls)
            {
                var loop = wall.Representation.Representations[1].Items[0];

                if (loop is IfcFacetedBrep)
                {

                    var _loop = loop as IfcFacetedBrep;
                    foreach (var face in _loop.Outer.CfsFaces)
                    {
                        foreach (var bound in face.Bounds)
                        {
                            var _b = bound.Bound as IIfcPolyLoop;
                            foreach (var point in _b.Polygon)
                            {
                                Debug.WriteLine(point.ToString());
                            }
                        }
                    }
                }
            }
        }

But:

Representations[] element must be IfcFacetedBrep (if it is IfcBooleanClippingResult, then i have no idea what to do)
Indexes of the Representations[], Items[] and other arrays are unknon
Walls can be as IfcWall (IFC 4), as IIfcWall (IFC 2x3) and the navigation through this objects are different

Do not use IFC.

My IfcWalls have all kinds of structures underneath them, ranging from polyline straight below the representation to facetedbreps and various other intermediaries. — Martien de Jong, Apr 30 '20 at 11:06

Getting the wall coordinates from IFC file with XBIM

1 Answers1